<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <title>websocket通讯</title>
</head>
<script src="https://cdn.bootcss.com/jquery/3.3.1/jquery.js"></script>
<script>
  var socket;
  function openSocket() {
    if(typeof(WebSocket) == "undefined") {
      console.log("您的浏览器不支持WebSocket");
    }else{
      console.log("您的浏览器支持WebSocket");
      //实现化WebSocket对象，指定要连接的服务器地址与端口  建立连接
      //等同于socket = new WebSocket("ws://localhost:8888/xxxx/im/25");
      //var socketUrl="${request.contextPath}/im/"+$("#userId").val();
      var socketUrl="http://localhost:9999/demo/imserver/"+$("#userId").val();
      socketUrl=socketUrl.replace("https","ws").replace("http","ws");
      console.log(socketUrl);
      if(socket!=null){
        socket.close();
        socket=null;
      }
      socket = new WebSocket(socketUrl);
      //打开事件
      socket.onopen = function() {
        console.log("websocket已打开");
        //socket.send("这是来自客户端的消息" + location.href + new Date());
      };
      //获得消息事件
      socket.onmessage = function(msg) {
        console.log(msg.data);
        //发现消息进入    开始处理前端触发逻辑
      };
      //关闭事件
      socket.onclose = function() {
        console.log("websocket已关闭");
      };
      //发生了错误事件
      socket.onerror = function() {
        console.log("websocket发生了错误");
      }
    }
  }
  function sendMessage() {
    if(typeof(WebSocket) == "undefined") {
      console.log("您的浏览器不支持WebSocket");
    }else {
      console.log("您的浏览器支持WebSocket");
      console.log('{"toUserId":"'+$("#toUserId").val()+'","contentText":"'+$("#contentText").val()+'"}');
      socket.send('{"toUserId":"'+$("#toUserId").val()+'","contentText":"'+$("#contentText").val()+'"}');
    }
  }
</script>
<body>
<p>【userId】：<div><input id="userId" name="userId" type="text" value="10"></div>
<p>【toUserId】：<div><input id="toUserId" name="toUserId" type="text" value="20"></div>
<p>【toUserId】：<div><input id="contentText" name="contentText" type="text" value="hello websocket"></div>
<p>【操作】：<div><a onclick="openSocket()">开启socket</a></div>
<p>【操作】：<div><a onclick="sendMessage()">发送消息</a></div>
</body>

</html>